Abaixo está uma instrução que descreve uma tarefa de geração de SQL, combinada com uma entrada que fornece mais contexto sobre os esquemas de tabela disponíveis. Escreva o código SQL que responda adequadamente à solicitação
 ###Instrução: Quantas famílias têm Yadkin como condado?
 ###Tabelas: CREATE TABLE north_carolina_counties_ranked_by_per_capita_income (north_carolina_counties_ranked_by_per_capita_income_id AUTO_INCREMENT PRIMARY KEY, County VARCHAR, Per capita income VARCHAR, Median household income VARCHAR, Median family income VARCHAR, Population INT, Number of households INT) CREATE TABLE césar_awards (césar_awards_id AUTO_INCREMENT PRIMARY KEY, Year INT, Group VARCHAR, Award VARCHAR, Film VARCHAR, Result VARCHAR) CREATE TABLE goalscorers (goalscorers_id AUTO_INCREMENT PRIMARY KEY, Rank INT, Name VARCHAR, S-League VARCHAR, Singapore Cup VARCHAR, Singapore League Cup VARCHAR, Total VARCHAR) CREATE TABLE viewing_figures (viewing_figures_id AUTO_INCREMENT PRIMARY KEY, Episode VARCHAR, 1st edition VARCHAR, 2nd edition VARCHAR, 3rd edition VARCHAR, 4th edition VARCHAR) CREATE TABLE hdr_tonemapping_and_exposure_fusion (hdr_tonemapping_and_exposure_fusion_id AUTO_INCREMENT PRIMARY KEY, Name VARCHAR, Merging to HDR from LDR images VARCHAR, HDR output ( EXR , HDR, Logluv , etc.) VARCHAR, Tonemapping VARCHAR, Exposure fusion VARCHAR)  
SELECT Number of households FROM north_carolina_counties_ranked_by_per_capita_income WHERE County = yadkin